The invention relates to an accelerometer with an inertia mass and a device for measuring an acceleration force acting on the inertia mass.
The inertia mass in known accelerometers of this type affects a piezoelectric element when an acceleration force occurs. The piezoelectric load thus caused is measured and represents the acceleration force which occurred. Accelerometers of this type are used, for instance, in electric shell primers or fuses or intrigger circuits for retention systems in motor vehicles. Such retention systems comprise, for example, an air bag or seat belts. Usage in these fields depends essentially on a long range dependability. It has been shown, however, that conventional piezo-ceramics have an irregular and uncontrollable behavior due to temperature or aging influences. My previous U.S. Pat. No. 4,083,254 granted on Apr. 11, 1978 discloses an accelerometer which requires the use of an optical prism resulting in a very precise yet expensive instrument, so that there is room for improvement in simplifying the structure substantially without loss of precision.